Title: Potential of a strain of the entomopathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) as a biological control agent against western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae)

Interpretive Summary: The western flower thrips is an important pest of ornamentals and vegetables that causes significant economic losses in both greenhouse and open-field plant production. The difficulties in using conventional synthetic insecticides to manage its populations has led to a growing interest in novel and more effective pest integrated management alternatives. Insect-killing fungus are insect pathogens with great potential for biological control. They can be applied in conjunction with other biological and chemical pesticides, predators and nematodes. Therefore, scientists with the USDA-Agricultural Research Service,Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida and the Chinese Academy of Agricultural Sciences investigated the virulence of novel strains of the insect-killing fungus Beauveria bassiana against western flower thrips. Strain RSB was highly virulent against western flower thrips in laboratory trials, and in greenhouse trials, this strain significantly reduced thrips abundance when sprayed on broccoli foliage. These results indicate that Beauveria bassiana strain RSB offers much promise as a biological control agent against western flower thrips.

Technical Abstract:
Five Beauveria bassiana strains were evaluated for control of western flower thrips. Strain RSB was the most virulent, causing 69-96% mortality at concentrations of 1×104 – 1×107 conidia mL-1, 10 days after inoculation of first instars. In greenhouse trials, RSB applied to broccoli foliage significantly reduced adult and larval populations.